exergue
Noun
Meaning
The small space beneath the base line of a subject engraved on a coin or medal. It usually contains the date, place, engraver's name, etc., or other subsidiary matter.
Source: Webster's dictionaryExamples
Inscription EKTΩP (Hektor) above, IΛIEΩN (Ilion meaning Troy) in exergue.
Many coins do not have an exergue at all, especially those with few or no legends, such as the Victorian bun penny.